Savings Certificates: clear directives needed

Clear directives are needed from the NBR as to whether one person with different individuals, such as husband & wife, father & son, father & daughter, mother & son, mother & daughter, so on and so forth, can purchase three-monthly profit giving Savings Certificates in Joint Names.
One of my relatives purchased two Savings Certificates ( three-monthly profit giving) in Joint Names, one with her elder daughter and the other one with her younger daughter, amounting taka three lakh and taka two lakh respectively from Dhaka GPO. When she went to collect the profits earned on the Certificates the pay clerk refused to pay any. According to Dhaka GPO, the same person cannot purchase Saving Certificates with different individuals in Joint Names.
If they can't, then how they have been issued the certificates in the first place, GPO's reply - it was a mistake!
As per the guidelines stipulated in the application form for Savings Certificates, (1) A person can purchase Savings Certificates worth up to Tk 50 lakh in Single Name or up to Tk 1 crore in Joint Names.
(2) If a person, either in single name or in joint names, purchases Saving Certificates above the limits, no profit will be given on the excess amount.
The relevant rules on Saving Certificates, therefore, do not stipulate that a person cannot purchase Saving Certificates in Joint Names with different individuals.
Here, the key is the ceiling or limit, which is Tk 50 lakh or Tk 1 crore as the case may be.
The family, having been deprived of the profits, is now living in tremendous hardship. She purchased the certificates from the money her husband received as retirement benefits and they fully depend on this.
May we request the Honourable NBR Chairman to kindly dispel mis-interpretation of the rules in regard to Joint Names and issue clear directives to Dhaka GPO to mitigate the sufferings of innocent buyers of the Savings Certificates like us.