how much will it cost to fix my oil tank pipe?

Whoops, unfortunately regulations state that any below ground fittings have to be inspectable, this would mean forming an inspection chamber if the broken pipe were to be joined, I may be cheaper to dig out the whole pipe and repalce, (depending on the legnth,) also how deep were you digging? oil line is meant to be atleast 600mm down, so unless you were digging for oil (no pun intended honest) you should not have been able to hit the pipe

I would suggest you get an OFTEC Engineer with OFT105E to have a look (i'm in E.Anglia)
www.oftec.co.uk will assist you to find a registered oil engineer near you

www.elanar.co.uk
September 2009