LLoyds questionaire for PPI Complaint

Hi,
Some advice needed please:
I called LLoyds bank to ask if I had PPI as I have been banking with them for 30 years - it turned out that I had loans and credit cards that I had forgotten about, but they wouldnt tell me the account numbers or confirm if I had PPI on the phone.

Next I recieved a questionaire for my accounts - again they did not reveal the account numbers or confirm any information about them, but I was expected to answer very detailed questions about where the PPI was sold and who did I speak to etc... as I can't remember taking the loan I can't answer these questions, and I didn't feel it was fair that they had witheld all the information they hold about my historical accounts which might help me get all the details. They also said that I had to return the questionaire to them within 14 days.

I do not think this is fair and I started trawling the MSE website - so I sent a letter back to Lloyds bank notifying them that at this stage I wanted copies of the loan agreements - I used the templated letter from the MSE website.

I recieved an acknowledgement of my letter saying I will hear from them by 19th March 2018 with information on my loan accounts.

Lloyds are still sending me text messages urging me to return the PPI questionaire to them 'as soon as possible' - I am ignoring them as I do not intend to communicate with them until I have full disclosure of any PPI I have paid.

Am I doing the right thing?

Thank you