Won’t extend my contract extend by 1-2 weeks

I have been a VM broadband customer having joined last January as I got a good deal with Volt on my 2 long term O2 phone contract. A year down the line I’m having to leave VM as I have had lots of issues with gadgets and smart devices dropping WiFi connections. When I joined VM in January I was told I could have wifi 7 within months, I was also told that the WiFi 6 modem would support 100 connections, but a year down the line I find I’m stuck on WiFi 6. The issue is that I have loads of smart tv’s, sky boxes, ring cameras, phones, PC’s plus around 12-15 smart plugs this time of year. I had an expert check my setup and I find that WiFi 6 cannot cope with all my appliances despite what I was told when I signed up. A few weeks ago I very sadly took advantage of the ability to leave the contract early without penalty due to the high price increase. Having agreed a termination date with VM I find that due to personal problems I could not switch to a new provider who offers WiFi 7 by the agreed date. I contacted VM to extend my termination by 2-3 weeks and got a flat NO reply. Does anyone know if there is a possibility to extend this date, or even to go onto a pay for a rolling month contract for an extra month and how to get this ?