
Both of the above replies are
very good advice.
If you continued to pay while you were in dispute, it would not prejudice the outcome of the complaint. In the event your complaint succeeded, any payment you had made that was later deemed not to be due would then be refunded, and your payment record (& potentially your
CREDIT record) would remain intact.
But, if you stopped payments, and your complaint later failed, you would then be overdue with your payments, in breach of contract, and at risk of a county court judgement and an adverse entry on your credit record.
JP