Can a bank be sued for irregularities in the foreclosure sale?

I need your advice, please. After failing to meet our monthly amortization for less than a year, the bank foreclosed our property. I was in the U.S. then, so when I got back, I looked at some documents. I am not a lawyer, but instinct told me that something was wrong. The first document I saw was the Notice of Foreclosure Sale. The date the sheriff signed it was July 3; and yet according to the certification of publication, it was published on July 1, 8, and 15. How can we publish a document on July 1 when it was signed only on July 3? Another thing is that the publication should be made on a newspaper of general circulation in the city or municipality where the sale is to be conducted. The newspaper outfit that was used for this is not of general circulation in the city because 80% of the people I talked with was not aware of this newspaper outfit. Would greatly appreciate your thoughts on this. Can these faults be basis for filing for annulment of foreclosure sale? Can I go ahead with the buy back of the property even if I filed a case against the bank? Thank you.