10 Years? thats not bad mileage
There is the facility to contact sky on their website.
Through my own experience with a similar issue I contacted sky by email saying that they should cancel the subscription as I was not able to enjoy the programmes through the existing fault and I had no extended cover on the box, it was over 12 months old.
They replied a day later with the offer of a free engineer visit to look at the problem and if needed replace free of charge the sky plus box, which they did, both parties myself and sky happy
Good luck.