Fell off ladder 6mths ago, broke left heel. Surgery great but a bad physiotherapist. Still can't tiptoe on my left feet. In extreme pain when I try.?

Pain. There are a lot of choices here . As already stated , the fracture may have involved the achilles tendon more than thought, scar entrapment is possible, tightening of the tendon due to casting or even the surgery itself may have damaged the tendon. Plantar fasciitis is possible , too. See your surgeon for the best help.
Achilles / arthritis. Either your fracture involved where the achilles attaches to the heel bone and it hasn't fully healed or you have developed arthritis of the joint between the heel and ankle bone (subtalar joint). This can be from damage at the time of your injury. See your surgeon. A ct scan may help find the answer.
See below. Depending on where the pain is, could be achilles tendinitis, plantar fasciitis, or even tarsal tunnel syndrome.