This may be a "card of last resort" for those with nowhere else to go. But you still have a right to expect efficiency and honesty. I mail my payments 10 days before they are due -- and twice this year the payment has posted one day late, with a hefty late fee on top of nearly 30 percent interest.
Other banks process payments in 3 - 5 days. So why does Merrick take more than twice as long? You can blame the postal service once, but twice in six months is more than a coincidence. I can't prove anything, but it looks suspciious.
I'd recommend steering clear of these guys unless you have no other options.