From a "chq presented before date" query, this is becoming a "property damaged" query !!
If the chq is returned when it was presented before the date of the chq, then sec 138 of NI act does not arise. You are safe on this.
The details of the query are not clear, but assuming that "equitable mortgage (EM)" was created to secure the loan, it is not the Bank's responsibility to take care of the property. The possession of the property is not with the Bank in case of EM (most common way of mortgage preferred by banks). However, in case there has been unjustified delay in handing over property docs after the loan was closed, there could be a case for deficiency in service.