where did the rm50 go?

Day 1 - Borrowed RM50 from Bill Gates (Promised to return after 5 days)
Day 5 - Borrowed RM50 from Madhatter (Promised to return after 5 days)
Day 6 (5 days due) - Returned Bill Gates his RM50 (Madhatter's RM50)
Day 10 - Borrowed RM50 from Brother from another mother (Promised to return after 5 days)
Day 11 (5 days due) - Returned Madhatter his Rm50 (Brother from another mother's RM50)
Day 15 - Borrowed RM50 from Ronald McDonald (Promised to return after 5 days)
Day 16 (5 days due) - Returned Brother from another mother his RM50 (McD's RM50)
Day 20 - Borrowed RM50 from Ironman (Promised to return after 5 days)
Day 21 (5 days due) - Returned McD his RM50 (Ironman's RM50)
Day 25 - Borrowed RM50 from KFC uncle (Promised to return after 5 days)
Day 26 (5 days due) - Returned Ironman his RM50 (KFC's RM50)
Day 30 - Borrowed RM50 from Bill Gates (Promised to return after 5 days, again)
Day 31 (5 days due) - Returned KFC his RM50 (Bill Gate's RM50)
[new month, rinse and repeat]