Awaitng payment since 22 April 2015

This is ridiculous my husband has done work (insurance job) for your company and now everytime we enquire about payment there is something missing. This is not acceptable this has been going on since the 22 April 2015 first we were dealing with a lady Duane and when no payment was coming through contacted her she said we must re send all documents to network blue we did that then we dealt with a gentleman Duwayne and in the emails it is clearly stated should there be anything outstanding contact details given. Everything has been sent off including banking details now today this Duwayne says the banking details must be on the invoice, this is stupid because there is no space on the invoice to write the banking details hence they were sent seperately and nothing is different. This company is pathetic and i am soon going to take this matter further because you cannot expect small businesses to carry you for 3 months without payment after job has been done.