The trick to a card like C1 is to max it out and pay it off before the statement reporting date. It will show your 'high balance' which is sometimes substituted for the credit limit in scoring models though I've heard some models totally disregard cards that don't report limit when factoring utilization.
If you pay it off after it reports, or your statement date, You take the chance that it will show maxed out for several cycles. I bought mine to zero two cycles ago and it has yet to update. Still showing a reporting date from two months ago.