Send them a invoice for £200 in lost revenue due to service interuptions and say you havnt paid because they owe you money.
Also tell them that they should have emailed you and you will charge them for legal costs as well if they really want to be stupid.
Say you will accept a full apology for the poor standard of the service instead however as long as you get a letter of retraction from the finance collectors and a full appology from them.
Thats if your feeling like causing trouble.
You could just leave it as well.
