Rubbish. Find yourself a good no-nonsense litigation lawyer with big slavering fangs keen on tasting developers flesh.
You do not need the developer’s permission at all to execute BGs.
They breach their end of the contract (no building license, late delivery, no LFO etc.), no problem, you claim on the bank guarantee which is an executive title and thus follows an executive procedure (which means there is no litigation involved, so even a conveyancing lawyer should do it). It takes a couple of months, mostly because banks take some hideous joy out of thwarting us on claiming on the BGs. But that’s their job and that’s what the client is paying us after all.
I differ from my colleague María because I believe that if the BG has expired you have no valid BG. And so you must renew it (your lawyer).
It will have to be a judge it seems who will have to cancel the contract providing you have good reasonable grounds for it.
Waiting 2 yers for off-plan is totally normal. Off-plan takes between 2-4 years. Perhaps you are refering to the fact that the developer has not delivered the property two years after the timeframe worded in the contract. In this case it would be late delivery. Two years is normally good enough to litigate providing the BL was granted in it’s day.