How can I get my car to start?

Chrysler voyager 2.5crd lx been off road 12 months started it eventually had new battery, only has 1 key no fob as partner list set n baby dropped set in nappy bin and bin got emptied b4 I realise no key, had key programme to car 2 yr ago, garage damaged barrel previous to new key as didn't use button to release key so key is removed all all points even wen car started. Sent to valeted last week and they keep call me as car won't start, after waiting 4 recovery I lock car then reopen and car start, then wen went to collect happened again, left it lock for half hr n started, but since valeted intermittent starting although full battery power then suddenly starts take for drive n leave running, arrive home on drive and turn off will not start, next morning starts, leave running, turn off after 20 min, then try start to take to school and nothing. Starts next evening every time then not started since Tuesday now Friday please help.