Customers who ordered an iPad 3G before June 7, 2010 have begun receiving claim forms for the class action settlement over misleading AT&T iPad data plans. Apple previously agreed to pay $40 to customers as the result of a suit based on AT&T advertising of an iPad unlimited data plan that was later eliminated. Some customers may also be eligible to receive a $20/month discount from AT&T on the carrier’s 5GB monthly plan. A website…