The hospital that you had surgery at should have samples storied.
Most tumor samples are still preserved using FFPE (formalin-fixed paraffin embedded). If you're lucky some of it will be frozen in liquid nitrogen. Both of these methods kill the tumor cells. Live tissue banking stores tumor material in such a way that cells are still viable and could be used for drug screening for example. This is by no means standard practice. There are probably other commercial services besides storemytumor but I don't have a list.
How much are you paying?I was able to get my bill from $50 to $35 because i was going to quit. Honestly, for us it was a complete waste of money.