Doubling credit card limits

My bank has sent me a letter advising me of doubling my credit card limit.The letter tells me that I should phone by the specified date if I do not want the increased limit.

I never requested for this increase.Why should I waste time phoning them and asking them to cancel this unsolicited increase.

The customers when phone the banks will have to go through various options , spend considerable time in getting to the right person and then identify themselves by answering the personal questions and then "request" for cancellation of the increased limit.

Do the banks think their customers' time is not important.

I use the credit card for convenience and not for getting free credit.I also never take "advantage" of their offer of paying pay only a small part on due date.

My credit card bank will never be able to trap me with increased credit limits and offers of payment of a small portion on due date( and keeping balance on very high interest rate )

I did phone the bank to cancel the increased limit but simultaneously as revenge got them to slash my original card limit too.And I am thinking of invoicing them for about 20 minutes I had to spend . Would I succeed .