To anyone in this situation, I can make a couple of suggestions. First, check your credit rating with Experian and Equifax. If your score is good, try taking your account to another bank. Sooner or later banks will have to start lending again.
If not, ring the grocer's charity Caravan for some free advice. Caravan set up a helpline last summer which among other things can help with money problems. They have access to financial advisors. The number is 0808 802 1122.