Thank you for your additional information.
At this point your first step needs to be sending them a letter informing them of the issues with your slab and include a copy of your lifetime warranty, since you cannot seem to contact them by phone. You can also post on their facebook page for all to see that you are having problems with the work they have done and have made numerous efforts to contact them but have not received any call back and ask them to contact you. This would likely elicit a response because they do not want anyone else to see they are not responsive to customers.
If they do not respond, your second step (to save money on an attorney or suing) would be to file a complaint with the Better Business Bureau and the State Attorney General's Consumer Protection unit, since under the state and federal warranty laws the attorney generals offices provide mediation
of warranty claims.
If the above steps cannot work on resolving your dispute, then you would have a right to sue in court for breach of warranty and the court would order a judgment in the amount of the costs to make the repairs.
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