I had a loan in 1998 with Halifax bank for £7000 however 6 months In I became ill and then made redundant so unable to pay but made agreement with them to pay £50 a month which I have done and never missed I've paid over £12000 in total and on last statement in November told owe £800 pound which is now down to £350 but I've just recieved letter saying debt been sold to moorcroft debt recovery who now want £2212.12 I'm totally confused and panicking as can't pay this need advice what to do.