That's a tricky situation, they're potentially waiting to give offers to the people with highest grades that apply via clearing. Did the places you contacted tell you when they would call you by? If you have another phone (a landline? Obviously don't be on the line that the unis are going to call you back on!) I would suggest pursuing a few more unis for clearing places, just in case your current options don't end up accepting you. Then phone back the places you already contacted in a couple of hours if you don't hear back yet. There's no limit to the number of verbal offers you can hold at once so feel free to try and get as many as you can to keep your options open.