Online renewal fail

My contract runs out in January and via the my virgin media app I was offered a reduced cost to renew now. I took up the offer online and received confirmation of the new cost and a new contract. However the my vrign app is still offering me reduced renewal cost and my latest bill,is at the old higher cost. Put in a complaint and was told they had no record of the new contract so I emailed them the copies I received. Nothing heard for the last 2 days even though I have emailed asking for an update. The next payment at the higher cost comes out of my account soon, is it worth ringing them (and waiting ages for a reply and then having to go,over everything again) or should I wait a bit longer for them to get back to me? I'm losing faith in them sorting this out.