India Post — scsc investment, problem of crediting interest directly to m sb account

Address: Kodagu, Karnataka, 571201

I have invested a sum of rs 15, 00, 000 in scsc scheme in my wife, s name which is the maximum limit allowed and the interest is directly credited to our joint sb account by the dept. I also invested rs 9, 00, 000 in scsc scheme and the interest also credited to our joint sb account. Now i invested another rs 6, 00, 000 in the same scheme which is under permissible limit. I also gave instruction to the dept that interest like other investments should be credited to our joint sb account. Now the dept official says that computer is not accepting it and advised me to open a seperat sb account. I am surprised to know this. Because all the deposites are under the limit. Then why my latest investment, s interest cannot be credited to our sb account. Kindly guide me regarding this matter.