CCS Collect Scam or HMRC?

I have been receiving two text messages from a company called CCS Collet. They are requesting payments through a provided link, but upon clicking, the website appears to be non-existent. The messages also contain a case number. I tried to call the number left in the message. However, I encountered automated responses, and upon entering my case number, I received a message stating that the case number is not recognized. I need to verify the legitimacy of this communication and company. If CCS Collet is affiliated with HMRC, I’ll need a formal letter from HMRC confirming this association. So far, CCS looks like a scam. The message claims that I have an outstading balance, but I paid £570.00 in February. Unfortunately, reaching out to HMRC via email has proven challenging, and due to time constraints, spending hours and hours on the phone waiting for an HMRC operator is not feasible. I need assistance with the authenticity of these messages and written confirmation by HMRC.

Hi A D 
Details of debt collection agencies used by HMRC can be found here:
HMRC and debt collection agencies
Thank you. 

None of my questions has been addressed.

Hi,

As per the link provided previously, CCS Collect are listed as a debt collection agency authorised by HMRC to contact you on our behalf, to discuss settling your debt. If you would prefer not to contact us by phone to discuss this, you can contact us by webchat or post.

Income Tax: general enquiries

Thank you.

Hi, About 2+ months ago I was contacted by CCS Collect (see above). After being in contact with them several times, I was informed that they had been instructed by HMRC to close my file because payment had been made directly to them. After a few weeks I started receiving communication from a different company - LCS - providing the same spill as CCS, but they were asking me to pay a different amount that CCS had in the past. Can you clarify what is happening, exactly? You're a governmental body, why are your ways so confusing? For any outstanding amounts you believe I owe you I will need to receive a confirmation letter from you clearly stating which company you're working with. Randomly being contacted by different companies asking for all sorts of amounts is not going to help.

Hi,
To clarify the amounts being requested and why, we would need to view your record and statement.
Contact HMRC by webchat or phone:
Self Assessment: general enquiries to allow us to do this. 
Thank you.

Thanks. Where do I access the webchat, please? Contacting HMRC by phone is out of the question as the waiting time is at least one hour, when lucky, and every time I call I am given contrasting answers to the same question. If you would simply allow people to set up repayment instalments online, that would be easier for everybody, including HMRC

Hi A D,
For the Self Assessment webchat, go to Self Assessment: general enquiries and select 'Ask HMRC online'.
Thank you.

Thanks! Unfortunately, the webchat is served by a useless bot. What is the best way to officially complain about HMRC? Also, when can I chat with a human being?

Hi A D,
You can see how to complain to HMRC here:
Complain about HMRC
You can contact HMRC to talk to an adviser here:
Self Assessment: general enquiries
Thank you.