Credit cards, miniterminals and how not to pay interest?

Question

Payment cards

It is possible to take credit cards for 400 thousand. Now this money is needed for investments. We take two cards. All credit cards have a 50 day interest free period.
Objective:
Pay nothing for the first card, prolonging the accrual of interest thanks to a grace period of 50 days and using the second card until the investment is justified in order to completely close the credit card.
That is, we spend one, and we transfer money from the second to the first, wait 50 days, then from it back to the second after 50 days.
Condition:
1) It is impossible to withdraw cash from an ATM, as it is interest, it is also impossible to transfer money from a credit card to another card - this is equivalent to withdrawal from an ATM and the percentage is similar.
2) the grace period is activated only if you bought something by bank transfer.
In banks, by bank transfer, managers mean purchases in a store with a card or in an online store, apparently here they mean that we are talking about legal entities, BUT HOW IS IT SO?
So, in order to implement the idea, we need to buy something from ourselves. But it’s pointless to use your legal face, it’s not worth it with the optimization of taxes and reporting.
And so, there is the next way out. Use non-cash payment not to a legal entity, but to an individual person (friend, acquaintance). To pay by bank transfer to an individual, you can swipe a card using miniterminals on an iPhone via iPay.
How do banks understand that I have made exactly the right purchase for them by bank transfer? AFTER ALL THIS IS IN A KIND AND WITHOUT CASH, AND OUTSIDE EVERYTHING IS SUITABLE, but in fact there are pitfalls and there is nothing to take banks for suckers?
(Well, they can also sell me a thread of a phone through such a terminal, but it turns out that this is an individual who does not pay taxes, and I will probably get into trouble buying something from them)

Answer 1

with such a scheme, you will get the same 5 percent of different commissions at least, in general, the scheme itself is stupid if you don’t have an easy way to cash out
, the easiest way is to collect loot from friends and pay for them with a card, let’s
say some kind of trip to a club in a company for 20 people it will come out just 100 thousand at a time, you take a hundred from them and pay with a card, so you have cash.