How do I escalate an issue with Cadent when they continue to fob me off? Complaints procedure ineffective and the Energy Ombudsman can't help for another 8 weeks.

On the 19/07/2023 Cadent replaced a gas pipe near our property. In doing so they managed to drill the new gas pipe through the middle of our waste pipe, essentially blocking it. What this means for us is that, once every couple of weeks, we have sewage overflowing from our drains and spilling out across the street. Then we have to call an emergency plumber who will come round and flush the sewage pipe at a cost of £200 a pop. Then of course we have to clean up the sewage. Obviously the alternative is to not use our toilet or shower and go elsewhere but that's hardly practical for an issue that's been ongoing over a period of months, and will likely continue for months more, especially when we both work from home. I've spoken to Cadent numerous times but have essentially just been messed around. They keep telling me it's "with their insurer who will call me back" but nobody ever calls me. **I raised a formal complaint with them a couple weeks ago but that mysteriously disappeared as when I called them up on Monday they had no record of it.** The result of this is that I only have an "official complaint" open with them for 1 day (provided that they definitely did log it this time) and, speaking to the Energy Ombudsman this afternoon, there's nothing they can do about it until the complaint has gone unresolved for *8 weeks*. This essentially means we have months more of blocked drains, shit everywhere and pissing money away getting it flushed. **Does anyone have any advice for us on how we might actually get this problem resolved more quickly?** I don't even though we could pay to fix it ourselves as presumably it will involve some gas work from Cadent themselves and it's not going to be cheap anyway. Thanks in advance!