If you just had it rebuilt at the start of the year it should still be under some type of warranty. I'd bring it back and have them fix it correctly or at the very least, check the pressures and diagnose the issue(s). If no type of warrenty... Then with a correct diagnosis, let the negotiations begin to get a mutual approved outcome of what to do next.
If you manually shift it, with the shifter, will it shift? When you are in first and the rpm's get to about 3k or so and you let off just a bit, will it shift? Do you still have reverse?
Besides that, test your tps sensor and map sensor. They both have a direct impact on the shifting.
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