Why use these agencies when you can go over the admission process to the Visa interview at the consulate on your own?
Start by looking for the University of your choice(online) and read through their respective admission process.
Most universities will require IELTS(Canada) /TOEFL(US) So jipange na 22-25k(the last time I checked)…some universities might also require evaluation for your Certificates,mostly it’s a course by course evaluation(WES) another 30k+.
Ooh remember there’s admission fee 80-100$ plus DHL fees for sending documents to the respective admission office…funny thing you can always be in touch with the admission office on call, around 5pm local time unacheka na tumanzi twa ofisi