Upvote:2
There is no appeal process for standard visitor visa. Since its easier and cheaper to submit the application again, with same information, but with a cover letter to point to the mistake made. The cover letter should be to the point that this is the case.
You can consult an immigration lawyer in UK (Not anyone in Pakistan). They are qualified to give you advise. But it will involve significant cost.
Details: https://www.gov.uk/find-an-immigration-adviser
Also, please look into this answer, to clarify your doubts regarding the bank statements.