We booked a car rental online with Holiday Autos for our visit to Rome. The confirmation stated that our provider was Payless and that we should collect the car at the Maggiore desk at the airport. We refused all extras as we had our own insurance.

When we returned the car the rep checked the vehicle, but didn’t give us any paperwork. We then received two messages on our home phone from Avis, asking us to return the vehicle and leaving an inaudible email address to contact. In a panic we emailed an address we located online, but had no reply. We tried to ring, but nobody answered.

We also tried Holiday Autos, with no success. We then received a telegram in Italian, again asking us to return the vehicle. I eventually reached Holiday Autos via Twitter and it gave me a telephone number but no one picked up.

Holiday Autos eventually obtained confirmation that we had returned the car. It gave me a £30 voucher by means of an apology, and said that Payless would be in touch with an explanation. Instead, we received an invoice from Budget with a different booking reference to ours and including a debit for €117 plus a €3 foreign transaction charge for personal accident insurance which we had not agreed to.

It claimed we had driven over 1,000km, when we barely did 100km, and erroneously described the car as white.

After a month of chasing, I received a reply from Avis, saying they’d refunded the €117.12, but only because “the rental agreement is not available in our system”.

I have no idea what Budget has to do with Maggiore, or why our rental got mixed up with someone else’s. RK, Chelmsford

You’re caught in a bewildering web of brands. Payless, Maggiore and Budget are all part of the Avis Budget Group, although you wouldn’t necessarily realise this.

Only when the Observer intervened did Avis acknowledge the wrong vehicle had been entered under your name. It says: “We have apologised for the inconvenience, and provided a refund for the additional charges levied in error, as well as a gesture of goodwill.”

That “gesture” is two days car hire worth €50, a small recompense for the month you spent fearing you would be charged for vehicle theft.

I hired a car from Avis Heathrow for nine days. On the second day it broke down. I was a woman alone with two children. Avis seems to pass on breakdowns to contractors and over the next seven hours two breakdown vehicles came but could not fix the problem or take me to my destination. Eventually, I managed to get Avis to pay for a taxi. By this time it was late at night.

I was told to go to the Oxford branch to pick up a replacement in the morning but the address it gave me was incorrect. Eventually, I tracked down the branch but staff knew nothing about my situation.

I did get a car, but not a refund of over £100 in taxi receipts and international mobile phone costs (I have a Singaporean contract). VF, Singapore

Again, Avis jumps to it when a headline looms and it refunded you your costs, plus 25% of the car hire and vouchers to entice your future custom. “Customer service is of the utmost importance to us,” it says.

If you need help email Anna Tims at your.problems@observer.co.uk or write to Your Problems, The Observer, Kings Place, 90 York Way, London N1 9GU. Include an address and phone number. Submission and publication are subject to our terms and conditions