At the end of May I hired a Ford Transit Custom from Thrifty to transport bits and bobs to a venue my partner and I hired in Derbyshire for our wedding that weekend. On returning the vehicle on the Monday, I was informed by the van hire manager during his post-assessment checks that he’d found two near-identical dents, one on each side of the van on the very lowest underskirting of the vehicle. It was an area I was not advised to check in our pre-hire assessment of the vehicle, and I hadn’t experienced any bumps or incidents of any kind during the hire period, so I was somewhat perturbed by the findings.

However, the manager informed me “there had been incidents of people trying to steal catalytic converters from that type of van” and that it would need further assessment. I left the vehicle with Thrifty expecting some form of communication over the next few days. I was surprised to receive a very cold letter the next day saying I’d damaged the vehicle and would be liable for up to £1,250 due to the insurance waiver I’d signed. This was followed by an email from the manager two days later, saying I had damaged the vehicle and would be liable to pay £700.

Since then a series of emails between myself and the manager, who is well-versed in this sort of thing and has used all of Thrifty’s pre-written contractual language, has lain fault at my door. I stated that to all my knowledge the dents had not occurred on my watch. I requested he showed me proof that the damage had not occurred in a previous hire, but he cited confidentiality laws as reason for not doing so.

I await a response from my solicitor. I believe I am being wronged by a company that has no interest in protecting the rights of the consumer, and instead appears to be taking advantage of its terms and conditions to actively profit from its customers’ misfortunes.

I was advised by a colleague to put a stop on any bank charges as he had heard of hire companies taking costs without consent. I did this, yet Thrifty has managed to extract the full amount without my consent. Is this legal or morally acceptable? CW, Bristol

We were sorry to hear that you lost £700 from your honeymoon fund. However, you signed, and therefore agreed to, Thrifty’s paperwork on all the key issues you are questioning, including assessment of damage, the debiting of charges for damage directly from your account, and the administration fees.

The pre- and post-rental report shows the condition of the vehicle at collection and return, both of which you signed. Thrifty told us the vehicle was very new, with only 170 miles on the clock at time of collection, and had only been rented on one occasion prior to this rental. It says there was no recorded damage. Regarding the possible theft of catalytic convertors, it said: “It would be unmanageable for any rental company to talk a customer through every eventuality that could occur throughout a rental, as you can imagine the list is endless.” But it denied the company’s vehicles had been a target for such thefts in this area.

A spokeswoman for Thrifty added: “Given all the correct documents were signed by CW, and he was aware of the damage, I believe our processes and procedures were followed appropriately and the damage correctly charged. There is no evidence to support his claim that he has been exploited – his vehicle may have been the target of a crime during the rental but unfortunately, although I am sympathetic, damage to the vehicle during a rental (regardless of how it may be caused) is the responsibility of the hirer unless in the case of a non-fault accident where a third party accepts full liability in which case the original excess liability will be refunded to the hirer”.

Thrifty has confirmed that the vehicle has been repaired and that the cost was £605.19. It has charged you £597.33 plus a £57 administration fee, but as a gesture of goodwill it will refund the latter.

We welcome letters but cannot answer individually. Email us at consumer.champions@theguardian.com or write to Consumer Champions, Money, the Guardian, 90 York Way, London N1 9GU. Please include a daytime phone number