S4rs expanding petrol tank

Has anyone any experience of this. Bought my S4rs new in 2008 and the tank has been slowly expanding since then,. I know its ethanol problems and poor quality of tank and has been talked about on forums particularly in USA. I should have acted on this when it first started years previously but its now got so bad I cant lock the tank down as strap now fowls the ignition pod . Has anybody had experience of this and can you tell me what you experiences were with Ducati re getting a replacement . No doubt I have left it to late now but any advice welcome