Trying not to be too ignorant, so my reason to dispute the debt is this quote? Thanks, jasonaaa

Hi, I defaulted on a Vodafone contract, the default date is 02/08/2014, the amount at that date was £1389.92. Lowell Portfolio 1 Ltd now have the debt and it was passed on to Lowell Solicitors who have sent me a Letter of Claim - 30 days to Prevent Legal Action. The 30 days is from 04/04/2019. Over the years I have ignored this debt and have received occasional letters asking for the money which I have ignored. Should I risk ignoring this and hope nothing happens and in 13 months the debt become statute barred due to being 6 years old? Or should I reply to the letter of claim complete Section 1 Box C stating 'I don't know whether I owe the debt' then Section 4 Box I stating 'I need more documents or information', and asking for copies of the written contract for the debt, a full statement of account, a calculation of interest claimed a copy of the notice of assignment of the debt and any other document you may suggest I ask for? Thanks in advance for any advice you can give.