Toyota incorrectly "Defaulted" me - help!

Cuilean

I bought a Toyota on HP in March 2003. At the time, I was working in a steady job in the city, and the monthly payments were no problem. They came out of my personal bank account.

In 2005, I relocated to Scotland for work. Unfortunately for me, when the contract ended, it took my new employer six months to get me cleared for my new office (I work with kids and need to be police checked). During these six months, my car payments were being paid by my boyfriend. We have a joint account together, and he paid into that every month. Normally, there's only a little money in the joint account, as it's intended for paying utility bills and council tax.

In August, I was cleared to start work, and called Toyota to ask them to switch payments back to my personal account. I distinctly remember the phone call, as the girl on the other end made some comment about how I was switching back to my original account. She took that month's payment out while I was on the phone.

Today, I have received a default in the post. Toyota claim that I have missed 2 payments, which made no sense to me as there's been plenty of credit available. A little digging around revealed that they'd not bothered to switch my direct debit back to my account, and have been taking their money from the joint account.

Yes, I'm an idiot for having quarterly instead of monthly bank statements, and I'm an idiot for not having them confirm the direct debit switch in writing, but if it's their mistake, can I ask for them to take the default off my account? We're supposed to be signing for our mortgage in the next fortnight, and I have a horrible feeling that'll be declined if Toyota don't sort this out pronto. What are my chances?

Please help me!