British gas 330?

We got a new system at the beggining of December Fitted by Scottish Gas !! Went with them for a reliable corgi fitter..
first of all we had a gas leak as soon as it was fitted and had the system shut down the next day . Now a few weeks later we have come home to no heating and an F13 error on the boiler it was originally showing as f1 we tried pushing the reset button and the boiler fired up and starting making a rumbling noise our 24 hour maintenance contract has stretched to 36 hours as they cant come out until wedensday any ideas from anyone ? with minus 10 degrees here its kinda cold