They Sent the Wrong Soil! Plagron Bat Mix instead of Light Mix for Autoflower

heh guys this is my first time grow and well heres my predicament..ordered plagron light-mix soil and big bud powder so i could control the amount of fertilizer being used.. but received the delivery today and they sent me bat mix instead..

so problem is that on the packet it says not to feed any nutes for the first 6 weeks! ive started growing in bandq seedling and potting compost and hoped to transplant them to plagron light mix outdoors once they are strong enough..so say 3 weeks indoor and remaining weeks outdoor..if the 6 weeks is the case i wont even get around to feeding my autoflowers the big bud nutes..

can anybody help me with this or should i ring them and tell them that they have sent the wrong grow media?? and would it be ok if i used big bud powder in a really small dose?

any help appreciated guys

any ideas guys?? what if i were to mix the bandq potting compost with the plagron? would that make a difference if i were to give some nutes?

surely someone can shed some light