Can a company claim legal expenses from me if the case was thrown out of court?

a few years back i fell behind with my rent,a re-payment plan was agreed and it was adhered to but despite this the housing ociation still took the case to court.i went to court to hear what would happen and i thought it was thrown out but now the problem is i have them chasing me for the court costs.i had a doorstep visit from a solicitor company today and explained the situation,he told me if the case had been thrown out then they have no right to claim court costs from me which is what i thought so now i am waiting to see if they have a court order for the money or not.i have tried writing to the housing ociation but they never respond,i went to citizens advice but they had no success either.can anyone help me out with what i should do next.I live in Scotland by the way.