Joined a Covid19 study. Felt positive about helpin...

Joined a Covid19 study. Felt positive about helping to save lives/end pandemic. Was told I would be compensated up to 740.
Clinic visists pay 101, phone 20 per time.
Started 1/2/2021. No check yet. Lots of excuses, lots of promises to help me.
Finally today, after 10 minutes on hold, was told by a cheerfully brusque person, that they issue checks on the 17th of the month. I had already been informed of that on my third question regarding payment. Well. Today I was informed that the first payment is 6 WEEKS after initial participation visit. Apparently there is problems with direct deposits.
Well. I didn't ask for direct deposit. I wanted checks mailed. Now, it seems, if I want my check to be mailed, it would be cut somewhere else, sent to Mpls office, then personally mailed to me. Or....she cheerfully offered me to pick up at Mpls location.
She did not read my frustration.
She did not read my mistrust.
I would not recommend joining a study here, unless you're selfless and don't care about compensation.
I will continue to participate in study because it's important.