Letter of Claim form details different from CC Claim Form. What to do?

[Everfen13]

In brief: A Letter Of Claim sent to me refers to a different dispite than the subsequent County Court Claim Form. Should I let the legal firm know OR use this as a defence on the County Court Claim Form?

I am in correspondence with a debt collector regarding two disputes about the same issue.
They sent me a Letter Of Claim regarding the first dispute which I completed and sent back within the deadline. They acknowledged receipt.
I then received a County Court Claim for the second dispute. It needs to be sent back this next week.
However, I then received a letter from the debt collector stating that as they had not heard from me regarding the Letter Of Claim, they were initialising court proceedings. This letter had the second dispute's details on.

So, they have started legal proceedings thinking they've sent me a Letter Of Claim for the second dispute when in fact the Letter of Claim was for the first dispute.
This means they haven't send me a Letter of Claim for the second dispute which, as I understand, must be done before legal proceedings are started.

My question is: Do I contact them and tell them OR do I use this as a defence on the County Court Claim Form?

Thanks!

[echat11]

Hi EVERFEN13

R0b Can you take a look and advise, many thanks.