They do need to be planted a lot deeper than when you buy them - maybe 3ins deeper some say more. Mine are all in their first year and look very sorry for themselves but are OK. The first year of pruning is hard to know what to do but most things I have read say cut back to 30cm for all types for the first year, feed (they are hungry plants)
Blood, fish and bone is good or Growmore is easier if you are not sure and mulch with compost. When they are in full growth give them tomato feed every couple of weeks. After this year, depnding on varirty will depend how you prune.
As you maybe didn't plant them deep then pile the mulch up high around the stem
Incidently mine are £2 ones as well