I have a similar PCN from the same place. I've just received 'Letter Before Claim' today. I wonder if you are able to share your reply to CVS? Did you send your reply by email or mail?
Will this work?
I disupte this debt because,
Firstly i only ever used my phone via wifi, there was never a notification regarding usage and data.
The rules regarding roaming usage has changed, the default was illegal and was disputed.
This matter is between O2 and myself.
The debt purchaser has yet to provide any or all of the required documentation.
Don't touch them owe me £500 since January 2019 make excuse after excuse. Seem they always have software problems sending money out. Keep saying they will call back or email nothing been chasing it now for 6 mths the phone staff always have the same banter we will chase it up and get back to you then nothing!