Drug dealers are so fucking unreliable, I once had to wait 5 days for my main guy to pick up, apart from him I had to suffer with about 5 grams of fucking chink for £50.
My favorite is when they say they'll be home in 15-20 minutes. 2 hours later you're still waiting for a phone call. Drug dealer time is annoying as shit. I have about 4-5 dealers that I rotate around, this helps to avoid this issue.